The echidna is an egg-laying mammal with spines and a long snout used to find ants and other prey.
Echidnas are monotremes, a rare mammal group that lays eggs rather than giving birth to live young. The only other living monotreme is the platypus. After a female lays a single soft-shelled egg, she incubates it in a temporary abdominal pouch. The hatchling, called a puggle, remains there while it feeds on milk released through pores because echidnas have no nipples.
Their spines are modified hairs made largely of keratin, the same tough protein found in human fingernails. Echidnas use powerful claws to tear open logs, soil and insect nests, then extend a long sticky tongue to collect ants, termites and other small prey. They have no teeth.
Echidnas are often confused with anteaters, hedgehogs and porcupines. They resemble all three superficially, but are not closely related to American anteaters, and their spines differ from the quills of porcupines. Four living echidna species are recognised, found in Australia and New Guinea.